An electroacoustic transducing device of this kind comprises: a magnetic circuit having a yoke, a magnet, and a pole piece; a vibration system having a diaphragm and a voice coil; and a frame which holds the magnetic circuit and the vibration system, and is configured so that the voice coil is placed in a magnetic gap. In the device, the diaphragm is placed on the magnetic circuit while an outer peripheral edge portion is bonded and fixed to the frame, and the voice coil in which a conductor wire is wound is placed in the magnetic gap while one end is bonded and fixed to the diaphragm.
In the thus configured electroacoustic transducing device, there is a conventional technique that, in order to improve the audio performance while reducing the diameter, a lead wire of the voice coil is drawn out from the voice coil at a position which is remote from the diaphragm, to the outside without being contacted with the diaphragm (see Patent Literature 1).
The conventional technique is effective also in the following point. In the case where the lead wire of the voice coil is drawn out from the voice coil at a position which is close to the diaphragm, when the voice coil and the diaphragm are to be bonded and fixed to each other, the one lead wire which is the winding start terminal is positioned on the inner circumferential side of the voice coil, and hence the winding start terminal must be drawn out toward the outer circumferential side of voice coil so as to bridge over the bonding face of the voice coil with respect to the diaphragm. Therefore, a surface rise corresponding to the diameter of one wire occurs in the vicinity of the terminal, so that the bonding face of the voice coil cannot be joined in parallel to that of the diaphragm. As a result, the bonding between the voice coil and the diaphragm becomes unstable, and the reliability of the bonding is reduced. In addition, the axis of the voice coil is inclined with respect to the vibration direction. Under the circumstances that reduced size and thickness are strongly requested and the size of the magnetic gap is restricted, when such an inclination occurs, the voice coil is easily contacted with the inner and outer components, or the yoke, the magnet, and the pole piece (see paragraphs [0002] and [0003] of Patent Literature 2).
In the above-described conventional technique, this problem does not occur.